Water-tube boiler.



A. ROSS.

WATER TUBE BOILER.

APPLIGATION FILED SEPT. 12,1913.

1,1 14,650. Patented 001;. 20, 1914.

4 "1 H h' x H H, W n,

5 ,..and which is already occupied by water,

ARTHUR ROSS, OF LONDON, ENGLAND.

WATER-TUBE BOILER.

Specification of Letters Patent.

Patented Oct. 20, 1914..

Application filed. September 1 2, 1913. Serial No. 789,470.

To all whom it may concern: 7 Be it known that I, ARTHUR Ross, a sub ject of the King of England, residing at London, England, have invented certain new and useful Improvements in Water-- Tube Boilers, of which the following is a specification.

This invention is for improvements in or relatingto water-tube boilers and has for its object to provide for'more eflicient cir culation and Working in the same.

WVater-tube boilers have already been proposed, see for example the British patent specification No. 29183 of 1911, of a-kind which comprises top and bottom drums at the ends of one diagonal of a polygonal figure, side drums at a level intermediate of that of the top and bottom drums, and sets of water-tubes connecting the drums to one another anddisposed along the sides of the polygonal figure, and comprising also a single furnace so constructed and arranged as to deliver its products of combustion first against one set of tubes that is at one side of said diagonal and is at a level above that of the bottom drum. It is to this kind of water-tube boiler that the present invention relates. I

The primary feature of the present invention consists in a water-tube boiler of the kind just described but so constructed that the total cross-sectional area of the second set of tubes is greater than that of the primary heating set of tubes, the primary heating set being that against which the furnace gases are first delivered, and the second set being that into which the primary set delivers. It has been foundthat if all the sets'of tubes are of equal cross- ,sectional area, the steam is not delivered at a sufficiently fast rate, from the set of tubes against which the furnace gases are first delivered, herein termed the primary heating set to obtain as good results as are possible. The steam, of course, is of considerably greater volume than the water from which it is formed and consequently the second set of tubes, to which the steam is delivered from the primary heating set have been unable to carry off the steam sufliciently rapidly when that second set has been of no greater cross-sectional area than that of the aforesaid primary heating set. I

In a type of polygonal water tube boiler in which two furnaces are employed, said furnaces supplying their products of combustion to two different primary sets of tubes in the boiler and thereby setting up op posingand mutually neutralizing circulatory currents, '5. e. in atype other than that above described, it has been proposed to make the second set of tubes of a greater total cross-sectional area than that of the two primary sets of tubes against which the furnace gases are first delivered, the said secondsets of tubes being, as above set forth, the sets into which the two prithe present invention, and Fig. 2 is an end elevation of the boiler'also partly in section.

Like letters of reference refer to like parts throughout the drawings.

In the drawings the boiler illustrated corresponds to that shown in Figs. 1 and 2 of the prior British specification No. 29183 of 1911, and any or all of the features covered in this prior patent may conveniently be used in connection with the present invention. Theboiler illustrated comprises four sets of tubes A, B, G and D, whi;ch connect together drums E, F, G and H- Theprodnets of combustion from the grateare' led first against the set of tubes A, z'.e., the primary heating set and then by means of suitable baffles, reach in succession the" sets B, C and'D, and then'pass to the flue. The feed is conveniently introducedat the drum Gr, while above the drum F a steam dome J is provided.

As will be seen from the drawings, the" set'of tubes B is of larger total cross-sec tional area than is the set of tubes A, in order tobe capable of readily taking all the steam that is formed in the tubes A and passed by theminto the drum E, as well as all the water from the same source. The" tubes employed are preferably quite straight, while the direction of flow of the furnace gases is preferably the same as that of the direction of flow of the water circulation, as described in the aforesaid British specification No. 29183 of 1911. Instead of making only the set of tubes B of larger cross-sectional area than the set A, it may be necessary in some cases to make one or both of the sets C and D also each of larger crosssectional area than the set of tubes A. In some cases this will be found to enhance the results obtained. In the drawings the sets B and C are both shown of larger cross-sectional area than the set A.

To obtain the diflerences in the cross-sectional area between the sets of tubes, the diameter or the number of the tubes employed may be varied. In the construction illustrated it has been preferred to show tubes of larger diameter, but it will be understood that either method of obtaining a difference in the cross-sectional area may be employed. According to another feature of the invention one or more of the drums E, F, G and H, may be fitted with an air vent. Sometimes it has been found that an airlock is formed in one or other of the drums and to obviate this a vent cock, such as K, connected to a perforated collecting pipe L may be employed. The pipe L extends from end to end within the drum and is situated at the highest point thereof, so that any air present in the drums may readily be vented by opening the cooks K. Another venting arrangement which may be adopted in some cases with advantage is to provide one or more tubes such as M connecting the top and the bottom drums. These connecting tubes may be controlled by valves if desired and may open to the atmosphere; in this way any air that may collect in the bottom drum may readily be vented, while, of course, the top drum can vent into the steam dome. a 1

It will be understood that the invention is not limited in its application to water-tube boilers having four sets of water tubes connected by drums, as it may usefully be employed in connection with other polygonal water-tube boilers. When applied to a boiler such as is described in the prior British specification No. 29183 of 1911,however, eX- cellent results are obtained.

hat I claim as my invention and desire to secure by Letters Patent is 1. A water tube boiler of general polygonal shape, comprising a mud drum, a steam and water drum, a feed water drum at one side and intermediate of the steam and water drum and the mud drum, a hot water drum at the other side and intermediate of the steam and water drum and mud drum, circulating tubes connecting the mud drum and the hot water drum, circulating tubes connecting the hot water drum and the steam and water drum, circulating connections between the steam and water drum and the feed water drum, circulating connections between the feed water drum and the mud drum, and a combustion chamber adjacent to the boiler structure, there being serial passages for the gases arranged to pass the gases over the circulating tubes, the circulating tubes between the hot water drum and the steam and water drum being of greater cross sectional area than the circulating tubes between the mud drum and the hot water drum, substantially as described.

2. A water tube boiler of general poly onal shape, comprising a mud drum, a steam and water drum, a feed water drum at one side and intermediate of the steam and water drum and the mud drum, a hot water drum at the other side and intermediate of the steam and water drum and mud drum, circulating tubes connecting the mud drum and the hot water drum, circulating tubes connecting the hot water drum and the steam and water drum, circulating connections between the steam and water drum and the feed water drum, circulating connections between the feed water drum and the mud drum, a central baflle within the boiler structure extending downwardly from the steam and water drum to a point adjacent to the mud drum, an intermediate baffle extending from the mud drum upwardly and outwardly and then upwardly between the central baffle and the feed water drum to a point adjacent to the circulating tubes between the steam and water drum and the feed water drum, a third bafile extending upwardly and outwardly, thence upwardly from the mud drum between the central baffle and the hot water drum to a point adjacent to the circulating tubes between the hot water drum and the steam and water drum, and a combustion chamber at the side of the last mentioned bafile, said battles being arranged to cause the products of combustion to pass serially over the tubes in the same direction as the flow of water through the tubes from drum to drum; substantially as described.

3. A water tube boiler of general polyg-V onal shape, comprising a mud drum, a steam and water drum, a feed water drum at one side and intermediate of the steam and water drum and the mud drum, a hot water drum at the other side and intermediate of the steam and water drum and the mud drum, circulating tubes connecting the .mud drum and the hot water drum, circulating tubes connecting the hot water drum and the steam and water drum, circulating connections between the steam and water drum and the feed water drum, circulating ;connections between the feed water drum and the mud drum, a central bafiie within the boiler structure extending downwardly from the steam and water drum to a point adjacent to the mud drum, an intermediate bafi le extending from the mud drum upwardly and outwardly and then upwardly between the'central bafliev and the feed water drum to a point adjacent to the circulating tubes between the steam and water drum and the feed water drum, a third baiiie extending upwardly and outwardly, thence upwardly from the mud drum between the central baffle and the hot water drum to connections between the mud drum and the.

hot water drum to provide the required space for the steam and water passing to the steam and water drum; substantially as described. v

4. A water tube boiler ofgeneral polygonal shape, comprising a mud drum, a steam and water drum above said mud drum, a feed water drum at the side of said drums and intermediate thereof, a hot water drum at the other side and intermediate of the steam and water drum and the mud drum, circulating tubes connecting the mud drum and the hot water drum, circulating tubes connecting the hot water drum and the steam and water drum, circulating tubes connecting the steam and water drum and the feed water drum, circulating tubes connecting the feed water drum and the mud drum. a combustion chamber at the side of the structure adjacent to the circulating tubes between the mud drum and the hot water drum, there being three bafiies within said structure and arranged to form four serial passes for the products of combustion so that the products of combustion will first pass over the circulating tubes between the mud drum and the hot water drum, then over the circulating tubes connecting the hot water drum and the steam and water drum, then over the circulating tubes connecting the steam and water drum and the feed water drum, and then to the stack over the tubes connecting the feed water drum and the mud drum; substantially as described.

5. A water tube boiler of general polygonal shape, comprising a mud drum, a steam and water drum above said mud drum, a feed water drum at one side and between said drums, a hot water drum at the other side and between the steam and water drum and the mud drum,,-circulating tubes between the mud drum and the hot water drum, circulating tubes between the hot water drum and the steam and water drum, circulating tubes between the steam and .water drum and the feed water drum, circulating tubes between the feed water drum and the mud drum, said circulating tubes be ing arranged so that there will be a closed circuit from the mud drum to the hot water drum, then to the steam and water drum, then to the feed water drum, then to the mud drum, a furnace at the side of the circulating tubes between the mud drum and the hot water drum, and bafliing within the boiler structure arranged to form serial passes for the products of combustion so that the products of combustion will pass over the circulating tubes in the direction of the flow of the water therein; substantially as described.

6. A water tube boiler of general polygonal shape, comprising a mud drum, a steam and water drum above said mud drum, a feed water drum at one side and between said drums, a hot water drum at the other side and between the steam and water drum and mud drum, circulating tubes between the mud drum and the hot water drum, circulating tubes between the hot water drum and the steam and water drum, said circulating tubes being of greater cross sectional area than the circulating tubes between the mud drum and the hot water drum, circulating tubes between the steam and water drum and the feed water drum, circulating tubes between the feed water drum and the mud drum, said circulating tubes being arranged so that there will be a closed circuit from the mud drum to the hot water drum, then to the steam and water drum, then to the feed water drum, then to the mud drum, and a furnace at the side of the circulating tubes between the mud drum and the hot water drum, and baffling within the boiler structure arranged to form serial passes for the products of combustion, substantially as described.

7. A water tube boiler of general polygonal shape, comprising a mud drum, a steam and water drum above said mud drum, a feed water drum at one side and between said drums, a hot water drum at the other side and between the steam and water drum and mud drum, circulating tubes between the mud drum and the hot water drum, circulating tubes between the hot water drum and the steam and water drum, said circulating tubes being of greater cross sectional area than the circulating tubes between the mud drum and the hot water drum, circulating tubes between the steam and water drum and the feed water drum, circulating tubes between the feed water drum and the mud drum, said circulating tubes being arranged some of said drums for exhausting the air so that there will be a closed circuit from the trapped therein; substantially as described.

mud drum to the hot Water drum, then to the In testimony whereof I have signed my steam and Water drum, then to the feed name to this specification in the presence of a water drum, then to the mud drum, a furtwo subscribing Witnesses.

nace at the side of the circulating tubes be- 7 tween the mud drum and the hot Water ARTHUR ROSS drum, bafiiing Within the boiler structure aritnesses: ranged to form serial passes for the prod- PERCY HEWITT, lQjllCllS of combustion, there being vents from WV. S. SKERTEN.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Iatents,

' Washington, D. G. 

